The field of the invention is cargo containers. From the beginning of manned flight, cargo of one type or another has been transported in planes. Since that time, the air freight industry has engaged in a constant effort to increase the efficiency of transporting cargo by air. For instance, it is customary to load commercial cargo into cargo containers on the ground, and then load the containers themselves onto the aircraft. FIG. 1 shows a conventional cargo container used for this purpose. This process saves time and is also more secure in-flight. Cargo is shipped in containers by air, after which, the containers are then unloaded directly onto trucks for shipping to final destinations. FIG. 2A shows a typical configuration for loading containers onto trucks.
However, disadvantages arise with this operation, when the trucks reach their destinations. The presence of Container A inhibits access to cargo in Container B and relatively few truck stations possess the capability to move cargo containers (which are typically more than 6 feet long on each edge and weigh about 500 lbs., or more, empty), such as Container A, off of the truck to allow direct access to Container B.
In the past, swinging doors for Containers A and B have been used. As shown in FIGS. 2A and 2B, door 2 of Container A swings inwardly while door 1 of Container B swings outwardly, thereby providing an accessway from the back of the truck through Container A to cargo in Container B. However, these types of swinging doors are expensive, heavy and are prone to fail after a relatively short period of service. Moreover, a significant amount of space must be cleared within Container A to allow the doors to swing inwardly into Container B.
To overcome these disadvantages, the present invention uses containers having roll-up doors. However, in use, cargo can shift or fall against a roll-up door. Thus, the roll-up door must be able to hold back or contain substantial loads. In addition, the container should advantageously be able to protect against rain entry, and be durable yet lightweight. The roll-up door should also be easily rolled up and down, and latched and locked into position. While roll-up door cargo containers have been known in the past, various disadvantages remain.
Thus, there is a need for an improved cargo container.